1. Field of the Invention
The present invention relates to a heat sink assembly, and particularly to a heat sink assembly having a fastener eliminating relative movement between a clip and a heat sink. The copending application Ser. No. 09/611,875 filed Jul. 7, 2000 is related hereto.
2. The Related Art
Many electronic devices, such as a central processing unit (CPU), operate in a limited temperature range and usually become unstable when their temperature is outside that range. On the other hand, the electronic devices generate a great amount of heat during operation. To maintain operation temperature within the proper range, a heat sink is often used to remove heat from the electronic devices.
A conventional heat sink 1, as shown in FIG. 3 of the attached drawings, is attached to a CPU 3 by a clip 2. A spring portion 5 of the clip 2 presses the heat sink 1 onto the CPU 3, with a pair of legs 6 engaging with a socket 4 on which the CPU 3 is mounted. However, the clip 2 is readily detached from the heat sink 1 due to undesired disengagement between the clip 2 and the heat sink 5 when a force is exerted on the clip 2 or the heat sink 1.
To meet the trend toward miniaturization in the computer industry, a flip chip package is broadly used. Referring to FIG. 4, a flip chip package comprises a substrate 6 and a flip chip 3 formed in the substrate 6. A conventional clip 2 is used to attach the heat sink 1 to the flip chip 3. However, the heat sink 1 is readily rotated about a die edge of the flip chip 3. Thus, the heat sink 1 cannot be fully in contact with the flip chip 3, which lessens the efficiency of removing heat from the flip chip 3.
It is strongly desired to provide a heat sink assembly which overcomes the above problems encountered in the prior art.